Geoscience Reference
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mic” studies.
thus it was at Kilauea that Wood determined the need for
an instrument capable of recording weak local earthquakes. the seismo-
graphs in his care at Kilauea convinced him that existing instruments were
unable to detect very weak shocks at distances of over one hundred kilo-
meters. this worried Wood greatly, because weak tremors “should be telling
harbingers of strong ones.”
122
Close to its epicenter, a weak tremor produced
faint, short-period oscillations, but sensitive seismographs attuned to dis-
tant quakes registered periods no shorter than six seconds.
123
Wood was
convinced that seismologists must prioritize the study of the seismicity of
their own regions, not the analysis of distant vibrations. to do so would
require new methods.
In fact, much of the remainder of Wood's career was devoted to defin-
ing the aims and methods of “regional” as opposed to “world” seismology.
Regional seismology comprised the study of the interrelations of various
problems: “geological,” “physical,” “human,” and “economic.”
124
thus a
major article in the
BSSA
in 1916 called for research into earthquakes “in
their importance to human life,” which in turn “inevitably will increase
immensely our knowledge of the physics of the earth, and of the specific,
dynamical behavior of the earth's crust in this province.” Wood looked to
europe and its many geophysical institutes as a model of “an enlightened
public policy.” He argued that the work of such an institute in California
should consist of the close coordination of “laboratory” (seismographic)
and “field” (geological and geodetic) studies, to be complemented by spe-
cial collaborations with engineers (whose concerns would otherwise be
outside the institute's “scientific” domain). taking up this theme again in
1921, Wood described the “strictly scientific” and “practical” dimensions
of earthquake research as “inextricably intertwined.” By “scientific,” Wood
here meant questions of structural and tectonic geology; the “practical”
dimension was “economic and humanitarian.” there could be no strict
division in the investigation of an earthquake: “the investigation of dam-
age is required, its causes, from both the natural and the structural point
of view, and its geographical distribution, all in relation to the underly-
ing geologic structure, and in relation to surface developments and their
bearing on living conditions (as sites for buildings, routes for transporta-
tion or conduits, and so forth), and the study of the problem from the
point of view of engineering science, education, protective legislation and
insurance.”
125
Wood's “regional seismology” thus recognized the com-
plex interplay of social and environmental factors in determining seismic
risk.
